The model

A 3d printer is a machine. A machine at your service…
Without a model, it won’t work!
Its computer part is waiting for instructions in the form of a file with a precise format to start printing.
A simple pencil will not be enough, it is necessary to integrate the volume and create a mesh that is all the more precise as the part to be made has a complex surface.

Choose a model

In fact, there are several ways of doing this

The 3d scanner

t is used to raise the surface of a volume. It can be any everyday object, or a model made in the workshop and that one wishes to reproduce individually or in series.
An interesting feature is that you can play with the scale and increase or decrease the size at will. Hello Russian dolls!
The online offer is quite large from very cheap to sophisticated. You can also use apps for smartphones.
To help you in your choice :
Primante3d, a very professional and complete website.
See also the excellent video of the Frères Poulain “an incredible free 3d scanner”.

A word of augmented reality with Yeehaw Wand a kind of spoon to capture in 3d the object of your choice
Things are moving very fast in this area. Keep up to date

Choose a ready-made model!

And yes, online model sites are abundant! There’s something for everyone…
A few examples:
Cults3d
All3dp
Free3d
And if you are interested in reproducing fossils, visit 3d-fossils.

Create your own 3d model

Thanks to Jonathan Keep for his remarkable work, by a talented ceramist.
https://wikifactory.com/@jonathankeep/3dfiles-for-clay-printing
It’s in English, but take the trouble to read it (with the help of DeepL if necessary…) and you’ll have a very good starting point, very well documented.

For our part we use Sketchup (exists in free version) quite easy to use.
Or Fusion 360® from Autodesk much more professional and powerful…

Be careful: if you’re going to do 3d drawing, start by practising on very simple shapes !
From model to print

The 3d printer works in successive layers. Once the model has been made, it must therefore be cut into as many “slices” as necessary. This is the work of the French “slicers” slicers. See a detailed explanation here
Don’t panic! Most 3d drawing softwares have an export function in .stl format, the format that the printer can read.
Life isn’t good!